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EP1909145A1 - Development Device and Process Cartridge and Image Forming Apparatus Including Development Device - Google Patents

Development Device and Process Cartridge and Image Forming Apparatus Including Development Device Download PDF

Info

Publication number
EP1909145A1
EP1909145A1 EP07117339A EP07117339A EP1909145A1 EP 1909145 A1 EP1909145 A1 EP 1909145A1 EP 07117339 A EP07117339 A EP 07117339A EP 07117339 A EP07117339 A EP 07117339A EP 1909145 A1 EP1909145 A1 EP 1909145A1
Authority
EP
European Patent Office
Prior art keywords
developer
conveyance path
supply
development
latent image
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP07117339A
Other languages
German (de)
English (en)
French (fr)
Inventor
Satoru Yoshida
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Ricoh Co Ltd
Original Assignee
Ricoh Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Ricoh Co Ltd filed Critical Ricoh Co Ltd
Publication of EP1909145A1 publication Critical patent/EP1909145A1/en
Withdrawn legal-status Critical Current

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Classifications

    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G15/00—Apparatus for electrographic processes using a charge pattern
    • G03G15/06—Apparatus for electrographic processes using a charge pattern for developing
    • G03G15/08—Apparatus for electrographic processes using a charge pattern for developing using a solid developer, e.g. powder developer
    • G03G15/0822—Arrangements for preparing, mixing, supplying or dispensing developer
    • G03G15/0887—Arrangements for conveying and conditioning developer in the developing unit, e.g. agitating, removing impurities or humidity
    • G03G15/0891—Arrangements for conveying and conditioning developer in the developing unit, e.g. agitating, removing impurities or humidity for conveying or circulating developer, e.g. augers
    • G03G15/0893—Arrangements for conveying and conditioning developer in the developing unit, e.g. agitating, removing impurities or humidity for conveying or circulating developer, e.g. augers in a closed loop within the sump of the developing device
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G15/00—Apparatus for electrographic processes using a charge pattern
    • G03G15/06—Apparatus for electrographic processes using a charge pattern for developing
    • G03G15/08—Apparatus for electrographic processes using a charge pattern for developing using a solid developer, e.g. powder developer
    • G03G15/0822—Arrangements for preparing, mixing, supplying or dispensing developer
    • G03G15/0877—Arrangements for metering and dispensing developer from a developer cartridge into the development unit
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G2215/00—Apparatus for electrophotographic processes
    • G03G2215/08—Details of powder developing device not concerning the development directly
    • G03G2215/0802—Arrangements for agitating or circulating developer material
    • G03G2215/0816—Agitator type
    • G03G2215/0819—Agitator type two or more agitators
    • G03G2215/0822—Agitator type two or more agitators with wall or blade between agitators
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G2215/00—Apparatus for electrophotographic processes
    • G03G2215/08—Details of powder developing device not concerning the development directly
    • G03G2215/0802—Arrangements for agitating or circulating developer material
    • G03G2215/0836—Way of functioning of agitator means
    • G03G2215/0838—Circulation of developer in a closed loop within the sump of the developing device
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G2215/00—Apparatus for electrophotographic processes
    • G03G2215/08—Details of powder developing device not concerning the development directly
    • G03G2215/0802—Arrangements for agitating or circulating developer material
    • G03G2215/0836—Way of functioning of agitator means
    • G03G2215/0841—Presentation of developer to donor member
    • G03G2215/0844—Presentation of developer to donor member by upward movement of agitator member

Definitions

  • Exemplary aspects of the present invention relate to a development device. More particularly, the present invention relates to a development device developing an electrostatic image with a developer having a toner and a carrier to form a toner image, and a process cartridge and an image forming apparatus including the development device.
  • Image forming apparatus of recent years are expected to stably produce high quality images with even image density even when images with high image area ratios are successively printed one after another.
  • an image forming apparatus including a development device having a developer conveyance mechanism is proposed, which feeds a developer vertically unlike conventional development devices, which feed a developer horizontally, an example thereof is shown in FIG. 1.
  • a related art development device 71 includes a development casing 72, a doctor 73, a developer carrying member 74, a developer supply mechanism 75, a developer agitation conveyance mechanism 76, and a developer collection mechanism 77.
  • a photoconductor drum 78 is arranged in the vicinity of the development device 71.
  • the doctor 73 controls the thickness of a developer carried on the developer carrying member 74 to supply a suitable amount of the developer to the photoconductor drum 7B for developing an electrostatic latent image thereon.
  • the developer which has been used for a development process at least once, is collected by the developer collection mechanism 77 and is conveyed in a direction of from the rear side to the front side of FIG. 1.
  • the collected developer is supplied to the developer agitation conveyance mechanism 76 through a first opening, not shown, that is disposed within a development region HH (shown in FIG. 2).
  • a toner supply mechanism not shown, disposed above the developer agitation conveyance mechanism 76 and in the vicinity of the first opening properly supplies an additional toner to the developer agitation conveyance mechanism 76 so as to increase the toner density to a desirable level.
  • the developer agitation conveyance mechanism 76 conveys the collected developer and the additional toner to the rear side of FIG. 1 while mixing.
  • the developer agitation conveyance mechanism 76 has a second opening A at a downmost stream side thereof relative to the developer conveyance direction to communicate with the developer supply mechanism 75 as shown in FIG. 2. Specifically, the developer agitation conveyance mechanism 76 supplies the developer to the developer supply mechanism 75 though the second opening A located within the development region HH. Subsequently, the developer supply mechanism 75 supplies the developer to the developer carrying member 74 from an upstream side to the downstream side thereof. As shown in FIG. 2, the developer supply mechanism 75 has a third opening B at a downmost stream side thereof relative to the developer conveyance direction to communicate with the developer agitation conveyance mechanism 76. Therefore, the developer supply mechanism 75 can supply the developer to the developer agitation conveyance mechanism 76 through the third opening B located within the development region HH.
  • the related art development device 71 can frequently cause developer accumulation in the vicinity of the first opening through which the developer collection mechanism 77 communicates with the developer agitation conveyance mechanism 76. Consequently, as shown in FIG. 3, the developer mechanism 77 can frequently cause excess supply of the developer at the downstream side thereof relative to the developer conveyance direction. In this case, the developer is supplied within the development region HH, the collected developer having a low density is flown into the developer carrying member 74, resulting in formation of an uneven density image.
  • One example attempts to arrange an opening outside a development region of a development device to supply a developer to each of developer conveyance mechanisms.
  • This opening arrangement can reduce the chance in that a low density developer is supplied to a developer carrying member.
  • a development device needs to increase the length of each of the developer conveyance Mechanisms in a developer conveyance direction by the length of the opening.
  • Such an opening arrangement can increase in size of the developer carrying member, resulting in a larger size of the development device and an image forming apparatus.
  • a development device includes a developer carrying member, developer collection conveyance path, and a developer supply conveyance path.
  • the developer carrying member rotates while bearing thereon a developer including a toner and a carrier to carry the developer to a development region, in which the developer carrying member faces a latent image carrier, to develop a latent image on the latent image carrier.
  • the developer collection conveyance path includes a developer collection, conveyance member collecting the developer from the developer carrying member after the developer on the developer carrying member passes through the development region.
  • the developer collection conveyance path is disposed obliquely above the developer carrying member and conveys the collected developer in a first direction parallel to an axis of the developer carrying member.
  • the developer collection conveyance path has first and second openings within a development region width.
  • the developer supply conveyance path includes a developer supply conveyance member supplying the developer to the developer carrying member.
  • the developer supply conveyance path is disposed below the developer collection conveyance path and conveys the developer in a second direction opposite to the first direction.
  • the developer supply conveyance path has third and fourth openings within the development region width. The developer on a downstream side of the developer collection conveyance path conveyed by the developer collection conveyance path is transferred to an upstream side of the developer supply conveyance path through the first and third openings. The developer on a downstream side of the developer supply conveyance path conveyed by the developer supply conveyance path is transferred to an upstream side of the developer collection conveyance path through the fourth and second openings.
  • an image forming apparatus includes a latent image carrier carrying a latent image thereon and a development device developing the latent image on the latent image carrier with a developer including a toner and a carrier.
  • spatially relative terms such as “beneath”, “below”, “lower”, “above”, “upper” and the like may be used herein for ease of description to describe one element or a feature' s relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, a term such as “below” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors herein interpreted accordingly.
  • first, second, etc. may be used herein to describe various elements, components, regions, layers and/or sections, it should be understood that these elements, components, regions, layer and/or sections should not be limited by these terms. These terms are used only to distinguish one element, component, region, layer or section from another region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present invention.
  • the scanner 300 reads the original on the contact glass 32 by pressing a start switch, referring to as an original reading operation.
  • the original is automatically transferred to the contact glass 32 so as to be read by the scanner 300.
  • the first and second traveling bodies 33 and 34 begin to travel, and the light source in the first traveling body 33 emits the light that is reflected from a surface of the original.
  • the mirror in the second traveling body 34 reflects the light.
  • the reflected light passes through the imaging lens 35 and enters into the reading sensor 36. Subsequently, the reading sensor 36 constructs image information based on the entered light.
  • the development roller 5 serving as a developer carrying member supplies the toner to the electrostatic latent image on the surface of the photoconductor drum 1 while moving a surface thereof in a direction indicated by an arrow I shown in FIG. 5.
  • the supply screw 8 serving as a developer supply conveyance member conveys the developer to a rear side of FIG. 5 while supplying to the development roller 5.
  • the toner supply opening 700 supplies the additional toner to a developer conveyance path including the supply conveyance path 9 and the collection conveyance path 7 of the development device 4.
  • the toner supply opening 700 is disposed at the upstream side of the collection conveyance path 7 relative to the developer conveyance direction within the development region width ⁇ so that the development device 4 and the image forming apparatus 500 can reduce the size thereof.
  • the development device 4 can secure an agitation conveyance distance to disperse the additional toner into the developer within the collection conveyance path 7.
  • the supply conveyance path 9 includes the supply screw 8 supplying the developer to the development roller 5, and conveys along an axis line direction of the development roller 5.
  • the developer falls from the supply opening 91 at the downstream side of the collection conveyance path 7 relative to the developer conveyance direction to the supply conveyance path 9 so that the collection conveyance path 7 can reduce the developer accumulation at the downstream thereof relative to the developer conveyance direction. Therefore, the collection conveyance path 7 can reduce the excess supply of the developer therewithin. Consequently, the development roller 5 can reduce the supply of the low density collection developer thereto from the collection conveyance path 7 through the supply conveyance path 9. Therefore, the development device 4 of the exemplary embodiment of the present invention can not only reduce the size thereof but can also reduce a frequency of the uneven density image caused by the low density collection developer supplied to the development roller 5.
  • the toner supply opening which supplies the additional toner to the collection conveyance path 7 is disposed at the upstream side of the collection conveyance path 7 relative to the developer conveyance direction. Therefore, the development device 4 can save the space thereof and can secure the agitation conveyance distance to disperse the additional toner into the developer within the collection conveyance path 7.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Dry Development In Electrophotography (AREA)
EP07117339A 2006-10-04 2007-09-27 Development Device and Process Cartridge and Image Forming Apparatus Including Development Device Withdrawn EP1909145A1 (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2006273096A JP5039352B2 (ja) 2006-10-04 2006-10-04 現像装置、プロセスカートリッジ及び画像形成装置

Publications (1)

Publication Number Publication Date
EP1909145A1 true EP1909145A1 (en) 2008-04-09

Family

ID=38759171

Family Applications (1)

Application Number Title Priority Date Filing Date
EP07117339A Withdrawn EP1909145A1 (en) 2006-10-04 2007-09-27 Development Device and Process Cartridge and Image Forming Apparatus Including Development Device

Country Status (3)

Country Link
US (1) US7715763B2 (ja)
EP (1) EP1909145A1 (ja)
JP (1) JP5039352B2 (ja)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102629093A (zh) * 2011-02-07 2012-08-08 夏普株式会社 显影装置和成像设备
US9026008B2 (en) 2012-01-10 2015-05-05 Canon Kabushiki Kaisha Developing device having developer conveying members

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7796922B2 (en) * 2007-04-20 2010-09-14 Ricoh Company, Ltd. Image forming apparatus having a magnetic field generating unit at the toner carrying section
US8045892B2 (en) * 2007-04-27 2011-10-25 Ricoh Company Limited Developing unit, process cartridge, and image forming method and apparatus incorporating an agitation compartment
JP5456960B2 (ja) * 2007-09-25 2014-04-02 株式会社リコー 現像装置、画像形成装置
US8126373B2 (en) * 2007-09-28 2012-02-28 Ricoh Company Limited Toner supply device and image forming apparatus that prevents toner from being scattered from the device
US8326189B2 (en) * 2009-09-08 2012-12-04 Ricoh Company, Limited Developing device, process cartridge, and image forming apparatus
JP2013222080A (ja) * 2012-04-17 2013-10-28 Konica Minolta Inc 現像器および画像形成装置
GB2511739B (en) 2013-03-11 2018-11-21 Zenith Oilfield Tech Limited Multi-component fluid determination in a well bore
JP6261314B2 (ja) * 2013-12-12 2018-01-17 キヤノン株式会社 現像装置

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002072642A (ja) * 2000-09-05 2002-03-12 Konica Corp 現像装置及び画像形成装置
JP2003122126A (ja) * 2001-10-09 2003-04-25 Canon Inc 現像装置及び画像形成装置
US20060008297A1 (en) * 2004-07-12 2006-01-12 Hajime Oyama Developing device, image forming apparatus and process cartridge
JP2006201753A (ja) * 2004-12-21 2006-08-03 Konica Minolta Business Technologies Inc 画像形成装置、現像装置、及び微粉回収方法
US20060204283A1 (en) * 2005-03-11 2006-09-14 Ricoh Company, Limited Development device and method capable of maintaining toner concentration at constant level without shortening life of developer, process cartridge, and image forming apparatus

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH1069155A (ja) 1996-05-29 1998-03-10 Ricoh Co Ltd 画像形成装置
JPH10274878A (ja) * 1997-03-31 1998-10-13 Toshiba Corp 現像装置
JPH11167261A (ja) * 1997-12-03 1999-06-22 Toshiba Corp 現像装置および画像形成装置
JPH11167260A (ja) 1997-12-03 1999-06-22 Toshiba Corp 現像装置
JP2002148921A (ja) 2000-11-10 2002-05-22 Konica Corp 現像装置及び画像形成装置
US6516174B1 (en) * 2001-07-17 2003-02-04 Toshiba Tec Kabushiki Kaisha Developing apparatus having developer regulating blade
JP2003173087A (ja) * 2001-12-07 2003-06-20 Canon Inc 画像形成装置
JP2005055531A (ja) * 2003-08-06 2005-03-03 Canon Inc 現像装置
JP4615921B2 (ja) 2003-11-21 2011-01-19 株式会社東芝 画像形成装置
JP4953634B2 (ja) * 2006-01-05 2012-06-13 株式会社リコー 現像装置及び画像形成装置

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002072642A (ja) * 2000-09-05 2002-03-12 Konica Corp 現像装置及び画像形成装置
JP2003122126A (ja) * 2001-10-09 2003-04-25 Canon Inc 現像装置及び画像形成装置
US20060008297A1 (en) * 2004-07-12 2006-01-12 Hajime Oyama Developing device, image forming apparatus and process cartridge
JP2006201753A (ja) * 2004-12-21 2006-08-03 Konica Minolta Business Technologies Inc 画像形成装置、現像装置、及び微粉回収方法
US20060204283A1 (en) * 2005-03-11 2006-09-14 Ricoh Company, Limited Development device and method capable of maintaining toner concentration at constant level without shortening life of developer, process cartridge, and image forming apparatus

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102629093A (zh) * 2011-02-07 2012-08-08 夏普株式会社 显影装置和成像设备
CN102629093B (zh) * 2011-02-07 2014-04-16 夏普株式会社 显影装置和成像设备
US9026008B2 (en) 2012-01-10 2015-05-05 Canon Kabushiki Kaisha Developing device having developer conveying members

Also Published As

Publication number Publication date
JP5039352B2 (ja) 2012-10-03
US20080085138A1 (en) 2008-04-10
JP2008090171A (ja) 2008-04-17
US7715763B2 (en) 2010-05-11

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